In some games, players start out with a unique situation, which may not be properly balanced with the other players. Often, a player will be eliminated before the end of the game, or be so far behind that he has no chance to win the game, and gives up trying.
The inspiration for this idea comes from Wolfgang_Kramer?, although similar concepts (or complaints) crop up repeatedly.
In some games players start out with a unique situation, such as BoardGame with a map, where players play countries. Different countries may have access to different resources. (AsymmetricalDistribution) The ability to play from a different perspective on repeated playing of the game can help Replayability, but care must be taken to keep the sides balanced. Otherwise, players will quickly learn which sides tend to do better or worse. Some players may develop self-defeating attitudes; "I have the worst side, so I can't possibly win, and there is no point in trying."
On the other hand, unbalanced sides have been used to handicap more experienced players.
At the end of the game, every player should have some opportunity to win. This is not to say that every player should necessarily have an equal opportunity to win. (Unless perhaps they have all been playing at a precisely equal level.) The game should allow a skillful player to build advantage throughout the game, (PositiveFeedback) but if the other players have no hope themselves, they are likely to become bored or frustrated, and there will be no excitement in the end of the game. (TensionCurve?)
Players should have an equal opportunity to win at the start of the game, and some opportunity to win at the end of the game.